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LF: 500 Permit emission’s bandwidth? New Data Mode - soon !

To: <[email protected]>
Subject: LF: 500 Permit emission’s bandwidth? New Data Mode - soon !
From: "Graham" <[email protected]>
Date: Thu, 6 May 2010 21:53:52 +0100
Importance: Normal
In-reply-to: <[email protected]>
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Thanks to  all  who  replied to the  request  for  Bandwidth  information.
 
After the  recent  ROS    EME and  500/1  500/8  data tests , I have been in conversation  with  Jose  over the  bandwidth constrictions part of the  MF permits , as we are 'all' aware there  are  other  contentions expressed elsewhere , however , I think in response to  the tests  conducted via this  reflector, and a series  of  emails over  the  possibility of a  faster  version of the  eme narrow mode,   Jose has  indicted that he will  prepare  a  narrow  data  mode , similar to the  existing ros  systems , but with a  bandwidth  of  100  Hz and a enhanced data  rate to a  'qso' mode   to  quote :-
 
''I think i have the solution. I could do a mode of 100 HZ at 6.25 baud. Speed it would be about 150 characters/minute, half of PSK31, and 8.5dB better than PSK31.''
 
I hope this  mode will  be useful to the  holders of permits allocating 100 Hz , we have  already the  comments  from  JIm and Andy  over the  issues of the legality of the  system , so  hopefully  once the  bandwidth  constriction's are met , this my  pave the  way  for  data  operations on 500  and  possibly 137 ? , as the  system will  be single  carrier, phase  continuous thus may  be amplified by class  e/d amplifiers and will  be resistant to  phase  distortion , which  from the  previous  ZL2AFP sounder tests  ( http://groups.google.com/group/uk500khz/web/zl2afp-psk-sounder ) explains the  poor  performance of psk on 500.
 
Tnx Graham
 
G0NBD
 
 
 
 

From: Graham
Sent: Thursday, May 06, 2010 2:08 PM
Subject: Re: LF: 500 Permit emission’s bandwidth? EU and Global ??

Thank you  , Rik,
 
From that  , its possible that  the  other  permits are  similar
 
Ok Tnx - G .

Sent: Thursday, May 06, 2010 1:19 PM
Subject: RE: LF: 500 Permit emission’s bandwidth? EU and Global ??

Graham,
 
the document that gives us access to 500kHz says 100Hz bandwidth, but does not say how many dB's the signal has to be attenuated at these limits.
 
73, Rik  ON7YD - OR7T
 

Van: [email protected] [[email protected]] namens Graham [[email protected]]
Verzonden: donderdag 6 mei 2010 13:30
Aan: [email protected]
Onderwerp: Re: LF: 500 Permit emission’s bandwidth? EU and Global ??

Ok Many  thanks'  for the  reply's
 
From that .... next is :-
 
From the  data, I assume that  100  Hz is the  common  limiting factor for a  narrow  band  data transmission  that  could be used by all  who 'wanted'  to  use it  ?..(noted on the  cw keying  speed  ~ BW)
 
So if a  value of  100 Hz is  specified, what  is the  'presumed'  roll-off of the power in the said bands ?, assuming that  the  original  concept was based on CW operation , which by  definition 'has to' generate sidebands , there must be an assumed  tolerance ?
 
Q  would the deployment  of a  system that  could   defined as   125 hz bandwidth  ie 100 Hz with   +/-  12.5 Hz  overspill , cause  a  technical  breach  of the  regulations  or  be  viewed as  occupying  the  'allocated' bandwidth  for a  telegraphy transmission ? ,
 
Taking that  spectral measurements in the  10  Hz  region are  perhaps  starting to  test  even the  best equipment, the  area  is perhaps a  little  empiric ?
 
I use the  word  telegraphy, purposely to view/observe the  situation interims of the  licence  conditions and not on the  basis  of  'mode' which like  Liverpool  and Everton have there  own sub cultures  but are still  football  teams ..
 
Thanks 
 
Graham
G0NBD
 
 
 
 

From: Graham
Sent: Wednesday, May 05, 2010 10:39 PM
Subject: LF: 500 Permit emission’s bandwidth? EU and Global ??

500 Permit emission’s bandwidth?

 

Can any one indicated  what is the  permitted  ‘telegraphy’  bandwidth  of the various ‘new’ 500KHz  licences  or  special  permits issued round the  EU and now the  rest of the  Globe ?

 

I have the impression that 100 Hz is the maximum ‘telegraphy’ transmission bandwidth, in some cases, eg , Belgium at 100 Hz .  Others appear to be some what wider or not defined ?.

 

Norway  is CW only  ? what is the  Dutch  allocation ? Southern Ireland ? ... etc

 

Are  Beacons defined by  mode or  bandwidth  ?

 

Tnx – Graham

G0NBD

 

(I use the  word  ‘telegraphy’ as defined by the  ITU R V.662-3 ,  please no  reference to key clicks ! )









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